linux-kernel - Re: [PATCH v2] soc/tegra: pmc: Support software wake-up for SPE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f70c6d62-a7fd-c153-932f-16886e46329b@collabora.com>
Date:   Mon, 3 Apr 2023 19:06:12 +0300
From:   Dmitry Osipenko <dmitry.osipenko@...labora.com>
To:     Petlozu Pravareshwar <petlozup@...dia.com>,
        thierry.reding@...il.com, jonathanh@...dia.com,
        p.zabel@...gutronix.de, ulf.hansson@...aro.org, kkartik@...dia.com,
        cai.huoqing@...ux.dev, spatra@...dia.com,
        linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Viswanath L <viswanathl@...dia.com>
Subject: Re: [PATCH v2] soc/tegra: pmc: Support software wake-up for SPE

On 3/30/23 20:06, Petlozu Pravareshwar wrote:
> The Sensor Processing Engine(SPE) can trigger a software wake-up of
> the device. To support this wake-up for the SPE, set SR_CAPTURE_EN
> bit in WAKE_AOWAKE_CNTRL register associated with the wake-up for
> the SPE. This SR capturing logic is expected to be enabled for wakes
> with short pulse signalling requirements.
> 
> Signed-off-by: Viswanath L <viswanathl@...dia.com>
> Signed-off-by: Petlozu Pravareshwar <petlozup@...dia.com>
> ---
> v1->v2:
> * Rebase the change on latest code.
> ---
>  drivers/soc/tegra/pmc.c | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index cf4cfbf9f7c5..2a2342eff622 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -3,7 +3,7 @@
>   * drivers/soc/tegra/pmc.c
>   *
>   * Copyright (c) 2010 Google, Inc
> - * Copyright (c) 2018-2022, NVIDIA CORPORATION. All rights reserved.
> + * Copyright (c) 2018-2023, NVIDIA CORPORATION. All rights reserved.
>   *
>   * Author:
>   *	Colin Cross <ccross@...gle.com>
> @@ -177,6 +177,7 @@
>  /* Tegra186 and later */
>  #define WAKE_AOWAKE_CNTRL(x) (0x000 + ((x) << 2))
>  #define WAKE_AOWAKE_CNTRL_LEVEL (1 << 3)
> +#define WAKE_AOWAKE_CNTRL_SR_CAPTURE_EN (1 << 1)
>  #define WAKE_AOWAKE_MASK_W(x) (0x180 + ((x) << 2))
>  #define WAKE_AOWAKE_MASK_R(x) (0x300 + ((x) << 2))
>  #define WAKE_AOWAKE_STATUS_W(x) (0x30c + ((x) << 2))
> @@ -191,6 +192,8 @@
>  #define WAKE_AOWAKE_CTRL 0x4f4
>  #define  WAKE_AOWAKE_CTRL_INTR_POLARITY BIT(0)
>  
> +#define SW_WAKE_ID		83 /* wake83 */
> +
>  /* for secure PMC */
>  #define TEGRA_SMC_PMC		0xc2fffe00
>  #define  TEGRA_SMC_PMC_READ	0xaa
> @@ -355,6 +358,7 @@ struct tegra_pmc_soc {
>  	void (*setup_irq_polarity)(struct tegra_pmc *pmc,
>  				   struct device_node *np,
>  				   bool invert);
> +	void (*set_wake_filters)(struct tegra_pmc *pmc);
>  	int (*irq_set_wake)(struct irq_data *data, unsigned int on);
>  	int (*irq_set_type)(struct irq_data *data, unsigned int type);
>  	int (*powergate_set)(struct tegra_pmc *pmc, unsigned int id,
> @@ -2416,6 +2420,17 @@ static int tegra210_pmc_irq_set_type(struct irq_data *data, unsigned int type)
>  	return 0;
>  }
>  
> +static void tegra186_pmc_set_wake_filters(struct tegra_pmc *pmc)
> +{
> +	u32 value;
> +
> +	/* SW Wake (wake83) needs SR_CAPTURE filter to be enabled */
> +	value = readl(pmc->wake + WAKE_AOWAKE_CNTRL(SW_WAKE_ID));
> +	value |= WAKE_AOWAKE_CNTRL_SR_CAPTURE_EN;
> +	writel(value, pmc->wake + WAKE_AOWAKE_CNTRL(SW_WAKE_ID));
> +	dev_dbg(pmc->dev, "WAKE_AOWAKE_CNTRL_83 = 0x%x\n", value);
> +}

To me this needs to be moved to the SPE driver, which should get the PMC
regmap handle and enable wake only when needed, similarly how it's done
by USB Tegra drivers that also need to configure PMC. Otherwise this
looks like a hack/workaround.

-- 
Best regards,
Dmitry